1. Field of the Invention
The present invention relates to an imaging apparatus and a method of starting the same.
2. Description of Related Art
There has been a demand for a reduction of the time from power-on to a ready-to-record state in imaging apparatuses such as digital cameras and digital video cameras so that a user would not miss recording desired scenes. It takes a comparatively long time (e.g. 5 to 6 seconds) from power-on to the ready-to-record state because of the need for checking the recording medium, such as a memory card. Specifically, presence or absence of free space, reproducible image data or the like is checked.
JP 2001-36785 A and JP 2002-237977 A disclose techniques for reducing the time necessary from power-on to the ready-to-record state (hereinafter, also referred to as “the start time”), for example.
JP 2001-36785 A discloses an information processing apparatus in which, if replacement of recording medium is recognized during power-off, necessary information is obtained from the recording medium even during power-off, and the obtained information is saved in a backup memory. In this case, the start time can be reduced by making use of the information saved in the backup memory at the time of the next power-on.
A technique employed for the electronic camera disclosed in JP 2002-237977 A is basically the same as the technique disclosed in JP 2001-36785 A. That is, according to the electronic camera of JP 2002-237977 A, management information on free space or the like is read out from recording medium in advance, and then saved in a memory. At the time of power-on, whether or not shooting is possible is determined, based on the management information saved in the memory. If replacement of a battery or recording medium is recognized, management information is read out from the recording medium again, and then saved in the memory.
However, the techniques disclosed in the above patent documents require that replacement of recording medium be recognized even during power-off. Because of this, a recognition means for recognizing replacement of recording medium during power-off and continuous power supply to the recognition means are indispensable. For imaging apparatuses that operate by a battery, an increase of standby power is not preferable because it directly leads to reduction of recordation/reproduction time.